If you hear the dogs, keep going. If you see the torches in the woods, keep going. If there's shouting after you, keep going. Don't ever stop. Keep Going. If you want a taste of freedom, keep going.

This moving quote, attributed to Harriet Tubman, occupies a revered place in popular American history. However, scholars cite no evidence that she actually said it. The exhortation appears to have originated from semi-fictional accounts of Tubman's life geared toward children in the 1950s and 60s.

Authentic or not, the quote undeniably rings true to Tubman in spirit. The words represent her. It is this same relationship between historical truth and its representation that Jeanine Michna-Bales investigates in her new book, Through Darkness to Light: Photographs along the Underground Railroad, in which the attributed Tubman quote appears opposite an image aptly titled Keep Going.

The Underground Railroad operated at its peak during the 1850s and 60s. Overall, an estimated 100,000 slaves made the dangerous, three-month, 1,400-mile journey to freedom. To avoid detection, they traveled in darkness, covering around 20 miles per night before stopping at a "station," where they would hide and rest in barns, caves, and beneath church floors. Although the US National Park Service has established certain waypoints along the Underground Railroad, the actual paths people took remain largely unknown.

Armed with years of solid research and an inexact map, Michna-Bales embarked on a photographic journey from former cotton plantations near Natchitoches, Louisiana, and threaded her way north through farms and villages, all the way to Michigan and the Canadian border. Her nighttime photographs thus represent something like what freedom seekers might have seen, as well as actual "depots" along the way.

The first impression of the book's images is that they are extremely dark. So dark, in fact, that their edges can sometimes barely be discerned from the black pages they're printed on. This intentional effect forces our eyes to adjust to the subtle color and light that give these images form. Like travelers on the Underground Railroad, we are challenged to navigate in near-complete darkness.

Michna-Bales pairs the images with quotes from historical texts, fiction, folklore, and spiritual songs, which help to contextualize the visual material. When light appears, it is often from the sky; the moon and stars were essential navigational tools along the Underground Railroad. For example, the Big Dipper—here referred to as "the drinking gourd"—points to the North Star, and a photograph of the star pattern appears alongside the verse, "For the old man is a-waiting / for to carry you to freedom. / If you follow the drinking gourd."

Indiana was usually the first free state that freedom seekers encountered, and the Ohio River, which forms the state's border with Kentucky, was such an important milestone that it was referred to as the River Jordan. Michna-Bales' panoramic photograph imagines the river as a mirror-like, convex arc that bends toward the approaching travelers, beckoning. Yet the dark land beyond promised neither freedom nor safety, as slave hunters and local law enforcement officials dogged the steps of freedom seekers all the way to Canada.

As a title for the series and book, Through Darkness to Light of course refers metaphorically to the journey from slavery to freedom. Indeed, the vast majority of these images convey the sobering darkness of slavery's shadow, punctuated only by the faintest light or the occasional, dim beacon. But Michna-Bales means it literally, too. In the final images, taken along the St. Clair River along the US–Canada border, a blinding sun rises.

In many cultures—Western and non-Western—the dark-light binary represents the poles of evil and good, respectively. Think of intellectual and spiritual enlightenment, for example. However, there exist legitimate questions about the racist implications of this deeply entrenched moral—and sometimes aesthetic—symbolism. As many theorists, philosophers, scholars, and sages have asked, how might equally entrenched forms of racist oppression be mitigated if this binary were to be switched or—more radically—obliterated altogether?Through Darkness to Light posits darkness as a process, a path, a way out that is essential to survival. Darkness, in this case, is a form of protection, and it is good. Aesthetically, these subtle and low-contrast images remind me of Teju Cole's brilliant essay about Roy DeCarava's work: "Instead of trying to lighten the blackness, he went against expectation and darkened it further. What is dark is neither blank nor empty. It is in fact full of wise light which, with patient seeing, can open out into glories."

While Harriet Tubman might not have actually spoken the words that open this essay, as someone who not only escaped slavery but risked recapture to travel the length of the Underground Railroad over a dozen times to rescue other enslaved people, she knew what it meant to persevere, to keep going. It is fitting—and no accident—that Michna-Bales should bring this work to our consciousness at a time when the country is again so bitterly divided, especially along the lines of race, class, and human rights. Her work prompts many questions, not the least of which is whether we, as a society, can keep going, and learn to see differently. —Laura M. André

The exhibition Through Darkness to Light: Photographs along the Underground Railroad is presented as part of PhotoSummer. See it at photo-eye Bookstore and Project Space until July 15. To view the portfolio online or inquire about print sales, please visit photo-eye Gallery.

Laura M. André is the manager of photo-eye's Book Division. She received her Ph.D. in art history from the University of North Carolina at Chapel Hill and taught photo history at UNM before leaving academia to work with photography books.